Go-Filter - Mobile Treatment System
The Go-Filter Mobile Treatment System is a modular trailer mounted water quality device designed to reduce turbidity levels in discharge waters at construction sites or industrial facilities. Turbidity reduction is accomplished without the use of environmentally harmful flocculants or chemicals. A trash pump mounted on the trailer conveys captured stormwater runoff from an adjacent collection pond, storage vessel, or other water source at a flow rate up to 250 gpm (16 L/s). Coarse material is first removed from the treatment flow through a gross pollutant separator and strainer.
Primary treatment is then accomplished by two cross-flow (centrifugal) sand filters configured in parallel. Backwash water is derived from the treatment flow process without the need for a separate backwash water source (e.g., tank). Treated water is discharged directly to a receiving water body or other conveyance mechanism. Both the filtration assembly and trash pump are powered by a single connection using electricity or generator.
The Go-Filter™ can achieve over 90% turbidity reduction with discharge levels on the order of 10 to 20 NTUs (Nephelometric Turbidity Units), depending on the influent level. As opposed to conventional sand filters, cross-flow filtration technology removes sediment particles to the submicron level, or 0.5 microns (0.0005 mm). The removal of these fine silt and clay sized particles provides for very low turbidity levels thereby meeting the most stringent NPDES permit discharge limits.
The Go-Filter™ is designed to provide a high level of turbidity reduction through the use of a gross pollutant separator and strainer for pretreatment followed by two cross-flow (centrifugal) sand filters configured in parallel. When compared to traditional sand filters, the Go-Filter™ achieves high performance efficiency using cross-flow filtration technology by maximizing contact time between the suspended sediment and the silica based sand filter media. This radial cross-flow design traps particles at the surface of the media bed instead of deep within a media bed such as a traditional sand filter. This allows the Go-Filter™ technology to use 50% less water for backwashing than traditional filters. Backwashing is accomplished using much less time and energy than conventional sand filters.
Traditional sand filters rely on forcing suspended particles deep into the media bed to improve sediment removal efficiency; hence, its ability to transmit water is diminished with increasing particle loading. This decreased flow capacity results in increased difficulty for backwashing since more water, time and energy is needed to remove the trapped material. While studies show that traditional sand filters can remove particles down to approximately 10 microns, high turbidity levels can still occur with increasing clay content (<1.5 microns) in the water. The Go-Filter™ technology achieves 95% solids removal to the submicron level, or 0.5 microns (0.0005 mm). This superior level of performance allows for clear water discharges from the Go-Filter™ Mobile Treatment System.
The Go-Filter™ treatment process is described in the following five steps:
Step 1. Water Supply and Flow Rate
The trailer mounted self priming trash pump conveys captured stormwater runoff from an adjacent collection pond or storage vessel at a flow rate up to 250 gallons per minute (gpm, or 16 liters per second, L/s). Since the Go-Filter™ can also treatment industrial wastewater, other means can be applied in order to direct water to the treatment system.
Step 2. Pretreatment
Pretreatment is accomplished at the selected flow rate when coarse materials are removed from the treatment flow through the use of a pollutant separator and strainer also positioned on the system’s trailer.
Step 3. Primary Treatment
Pretreated water continues at the selected flow rate to two cross-flow sand filters configured in parallel on the trailer. Each filter consists of a 36-inch (91 cm) diameter stainless steel, ASME certified vessel. The filtration assembly also includes an automated control panel and associated switches, valves, strainers and tubing. Both the filtration assembly and trash pump are powered by a single connection using electricity or generator.
Step 4. Backwash
Both cross-flow filters are self-cleaning through the use of backwashing cycles. Filter backwashing utilizes process water without the need for a dedicated water storage vessel. Backwash cycles are triggered automatically by pressure differentials resulting from particle accumulation within the filters and have typical durations of four to eight minutes.
Step 5. Discharge
Post-filtration (treated) water exits the filters under gravity flow through a flexible hose at the same flow rate of the trash pump. The discharge hose runs from the filter assembly to a designated discharge point away from the trailer. No additional treatment is necessary once water is discharged from the system.